The present invention relates to an image transmitting method for transmitting image data of a camera such as a digital camera and also to an image transmitting system for carrying out said method. In particular, the invention relates to an image transmitting method for transmitting an arbitrary image region on a picture of a camera, and to an image transmitting system for carrying out said method.
In the past, as the image transmission mode of this type, a protocol for digital camera for transmitting image data over a network such as IEEE 1394 serial bus has been standardized in 1394TA. In the 1394-based Digital Camera Specification Rev. 1.20, a method for transmitting only the image data in a designated part of the region among the entire image region is defined.
Here, referring to FIG. 5, description will be given on a part of the conventional image transmitting method relating to the present invention. FIG. 5 explains a method for designating an arbitrary image region (which may be all or a part of a picture) on a picture taken by a camera. FIG. 5A is a drawing to show a region on the picture and dimension, and FIG. 5B indicates parameters for designating the region
Extent (size) and position (expressed as A, B, Cxe2x80x2, Dxe2x80x2, E, F, G, and H) of each portion of the effective region given in the parameters of FIG. 5B represent extent (size) and position of portions shown by each of the corresponding symbols (A-H) in the image region shown in FIG. 5A. That is, a symbol xe2x80x9cAxe2x80x9d given in (1) of FIG. 5B denotes the maximum value of an extent of an effective region (an image region designated for transmission; the same applies hereinafter.) in horizontal direction. xe2x80x9cBxe2x80x9d represents the maximum value of an extent of an effective region in vertical direction. A symbol xe2x80x9cCxe2x80x2xe2x80x9d given in (2) of FIG. 5B represents a designation minimum unit of an effective region in horizontal direction, and xe2x80x9cDxe2x80x2xe2x80x9d represents a designation minimum unit of the effective region in vertical direction. A symbol xe2x80x9cExe2x80x9d given in (3) of FIG. 5B represents a position of an effective region in horizontal direction, and xe2x80x9cFxe2x80x9d represents a position of the effective region in vertical direction. xe2x80x9cGxe2x80x9d given in (4) of FIG. 5B represents a size of the effective region in horizontal direction, and xe2x80x9cHxe2x80x9d represents a size of the effective region in vertical direction.
Next, referring to FIG. 5A and FIG. 5B, operation of the conventional image transmission will be described. First, on a register (not shown) of a camera, the maximum value of an extent of the effective region (A: horizontal direction; B: vertical direction) and a designation minimum unit (Cxe2x80x2: horizontal direction; Dxe2x80x2: vertical direction) of the effective region are set. These values are acquired by the control unit, which requests transmission of the image region. Based on the data thus acquired, a position of the effective region (E: horizontal direction; F: vertical direction) and a size of the effective region (G: horizontal direction; H: vertical direction) are determined so that the region is an integral multiple of the designation minimum unit of the effective region and within the maximum value, and these are set on the register of the camera.
After these parameters are set in the register of the camera, the image transmission procedure is started, and the image data of the effective region designated above are transmitted over a network.
However, in the conventional image transmitting method as described above, the designation minimum unit (Cxe2x80x2, Dxe2x80x2) for designating the position (E, F) of the effective region for image transmission and the designation minimum unit (Cxe2x80x2, Dxe2x80x2) for designating the size (G, H) of the effective region, the same designation minimum unit is used. Accordingly, in case there is a restriction on the setting of either one of the designation minimum unit of position of the effective region or the designation minimum unit of the extent of the effective region, the restriction on one of them is also applied or extended to the other, and free designing cannot be carried out.
As an example, when an image of YUV 4:1:1 is transmitted, number of pixels in horizontal direction must be set to a multiple of 4. In this case, the designation minimum unit (for the extent and the position) of the effective region must be set to a multiple of 4. Then, problems arise that position of the effective region cannot be designated by one pixel unit.
To solve the above problems, it is an object of the present invention to provide an image transmitting method and an image transmitting system for carrying out the method, in which a designation minimum unit for designating the position of the effective region and a designation minimum unit for designating the size of an effective region are set in such manner that these are independent from each other, and even when there is a restriction on one of these designation minimum units, the restriction on one of them is not extended or applied to the other.
In the image transmitting method and the image transmitting system of the present invention, a designation minimum unit (I, J) for determining the position of the effective region is set independently and separately from a designation minimum unit (C, D) for determining the extent of an image region to be transmitted (hereinafter referred as xe2x80x9ceffective regionxe2x80x9d).
According to the present invention, the designation minimum unit for determining the extent of the effective region and the designation minimum unit for determining the position of the effective region are set independently from each other. As a result, even when there is a restriction on one of the designation minimum unit for designating the position of the effective region and the designation minimum unit for designating the size of the effective region, it can be designed in such manner that the restriction on one of them is not extended or applied to the other.
The image transmitting method according to the present invention comprises the steps of setting the maximum value of an extent of an effective region in horizontal direction and vertical direction, a designation minimum unit of an extent of the effective region in horizontal direction and vertical direction, and a designation minimum unit of a position of the effective region in horizontal direction and vertical direction, setting a position and a size of the effective region designated from an external operation/control unit, and inputting only an image data included in the effective region and outputting it to outside. The values of the designation minimum unit of the extent of the effective region in horizontal direction and vertical direction are set to values independent and separate from the values of the designation minimum unit of the position of the effective region in horizontal direction and vertical direction. Even when there is restriction on one of the designation minimum unit for designating the position of the effective region or the designation minimum unit for designating the size of the effective region, it can be designed in such manner that the restriction on one of them is not extended or applied to the other.
In the image transmitting method of the present invention, the designation minimum unit of the position of the effective region is set to a value smaller than the designation minimum unit of the extent of the effective region. Because the designation minimum unit of the position of the effective region is set to a value smaller than the designation minimum unit of the extent of the effective region, and this makes it possible to set the shifting of the effective region in more elaborate manner.
The image transmitting system of the present invention comprises image acquisition means for converting an image input obtained by photographing to a digital electric signal, transmission means for processing the digital electric signal received from the image acquisition means and for outputting pixel data of the effective region to be transmitted to an external device, and transmission control means for supplying an effective pixel value setting signal for setting to transmit pixel data based on a command from an external operation/control unit to the transmission means. The transmission control means is designed to hold the maximum value of the extent of the effective region, the designation minimum unit of the extent of the effective region, and the designation minimum unit of the position of effective region. The designation minimum unit for designating the position of the effective region is set separately from the designation minimum unit for designating the size of the effective region. As a result, the size of the effective region and the position of the effective region can be set without any restriction on each other.
In the image transmitting system of the present invention, the designation minimum unit of the extent of the effective region is set to a value independent and separate from the designation minimum unit of the position of the effective region. The designation minimum unit for designating the size of the effective region is set separately from the designation minimum unit for designating the position of the effective region. As a result, the size of the effective region and the position of the effective region can be set without receiving any restriction on each other.
In the image transmitting system of the present invention, the designation minimum unit of the position of the effective region is set to a value smaller than the designation minimum unit of the extent of the effective region. As a result, the designation minimum unit of the position of the effective region is set to a value smaller than the designation minimum unit of the extent of the effective region, and the shifting of the effective region can be set in more elaborate manner.